An axiom of clinical medicine, particularly in oncology, is that early diagnosis of disease allows for more effective therapy and better clinical outcomes for patients. A major goal of SomaLogic is to improve the quality of life for patients through individualized medicine based on the quantitative analysis of proteins using multiplexed arrays of proprietary nucleic-acid based capture reagents, aptamers and photoaptamers. The overall objective of our research efforts in cancer is to develop assays and algorithm-based analysis systems for the diagnosis and management of patients at with various malignancies using photoaptamers directed against proteins that are associated with solid tumors (known cell markers, tissue specific proteins, transcriptional regulators, etc.) or the host response to these tumors (inflammatory and immune mediators). The specific aims of Phase I are to: 1) develop specific SELEX (Systematic Evolution of Ligands by EXponential Enrichment) protocols for generating photoaptamers to proteins expressed using the three most common affinity tags employed by the protein expression laboratory of the NCI and 2) develop high affinity photoaptamers to at least 20 cancer-related proteins to demonstrate protein versus affinity tag selectivity and build content for the photoaptamer-based protein measurement array. In Phase II, once the affinity-tag SELEX protocols have been developed and used to discover new photoaptamers, these new photoaptamers will be incorporated into SomaLogic's existing photoaptamer array for use in clinical studies of a number of different cancers, including lung cancer. Phase III will include the final studies needed to validate those biomarkers and algorithms that prove to be the most robust in Phase II and to develop the systems and protocols needed to provide these diagnostics to the clinical community via CLIA-compliant laboratory services.